The lens is designed NOT to be sharp from f2.8 to about f5.6, but
has a 'sharp' range from around f8 upwards.

Also, as it doesn't have an 'A' setting, it will not work correctly
as the *istD has the "crippled" KAF mount. It will only meter
correctly in the soft range, in the sharp range it will probably
underexpose as mentioned in B Dimitrov's pentax site.

If you want a good portrait lens for the *istD, you are better off
with either the 77 Ltd or 85mm f1.4 although with the *istD I would
personally find themm a bit too long. I would have thought your
50mm F1.4 would be excellent for portrait work, as I find my 50mm
macro an ideal focal length on my *istD as it equates to a 75mm
lens on FF, which is often regarded as the "ideal" for portraiture.
If you want a soft effect I suggest using a Cokin (or similar) soft
filter set, or indeed do it as post processing in Photoshop.

The 28 f2.8 or the 35 f2 are both cracking lenses, the 35 f2.0 is
very well regarded and is small, light and bright with superb
optical charictaristics.. I would love one for my MZ-S but as I
only shoot 10% in film now, I cannot really justify to myself
(yet), maybe when Pentax make a FF DSLR!

I actually like a 35mm (in FF speak) as a walk about lens, so I
bought the Pentax FA* 24mm f2.0 for my *istD, which I love.

Cheers
--
Richard Day - 'Carpe Diem!'
Gloucester UK

The FA 50 1.4 is curretly my favorite portrait lense (and I shoot alot of portraits), but I would also like to have someting in the longer range to work with. I guess I should just save for the 77 limited (which is what I wanted in the first place).

I already have a 24 2.8 macro (Screw mount) which is really nice, and sharp, so I cannot justify another 24, even if it is auto focus. I guess I just go find a FA 35 2.0.